1. Field of the Invention
The present invention relates to light signal receiving method, and more particularly, the invention relates to a light signal receiving method and device thereof applicably to range finders, and capable of both long-distance measurement and short-distance measurement.
2. Description of the Related Art
In conventional pulse laser range finders, current noise is produced during measurement. After conversion into time domain, the location of the current noise is at location distance 7˜10 meters from the ranger finders meaning noise and true signals cannot be differentiated between when the distance from the target to the range finder is within 10 meters. To address this problem, small signal noise can be eliminated using a high reference voltage level provided by a single comparator. However, this method also eliminates the small signal pulse needed for long distance measurement, hence a long distance target cannot be measured.